Method of manufacturing playing ball centers



Feb. 6, 1940. c, c, D V ET AL 2,189,514

METHODOF MANUFACTURIIQG PLAYING BALL CENTERS Original Filed May 4, 193

INVENTORaS Cad/on C 0:: w:

ATTORNEY.

Patented Feb. 6, 1940 UNITED STATES METHOD OF MANUFACTURING PLAYING BALL cnnrnas Carlton C. Davis, Glen E lyn. and Jesse Howell Gregory, Wheaton, 11]., assignors, by mesne assignments, to Wilson Sporting Goods Company, a corporation of Maine Original application May 4, 1936, Serial No.

77,810. Divided and this application October 18, 1937, Serial No. 169,588

4 Claims.

This application is a division of our copending application S. N. 77,810 filed May 4, 1936, now Patent No. 2,117,083.

Our invention relates to methods of manufac- 5 turing playing ball centers which are made of fibrous substances.

Playing ball centers have long been made of unwoven fibers which are compressed or molded into spherical forms of sizes suitable for the purposes intended. These forms are designed to be incased in a filamentous winding and a flexible cover to provide finished playing balls.

According to the methods of manufacture now generally in use, suitable fibers such as, for instance, kapok are supplied in bales in which loose lumps or wads of fiber are compressed together. When these lumps or wads are removed from the bale, they are usually emptied into a container which is convenient to an operator whose duty it is to compress them together in the molded form. The amount of fibers used in each ball center is determined by weight, the lumps or wads being placed on a scale until the scale indicates the predetermined weight. The mass of loose fibers on the scale is then placed in a mold and subjected to sufiicient pressure to cause them to retain a spherical form. Upon removal from the mold the compressed fibers. expand unevenly and therefore the ball centers vary considerably both in size and in form. Thread is then wound about these ball centers. This winding operation changes their shape somewhat because the thread wound about the centers compresses the fiber unevenly and as a result the wound centers vary both in size and in shape.

This variation not only causes the completed ball to vary as to size, form, and performance but is also a constant source of annoyance and expense to the manufacturer. This is partly due to the fact that these wound centers are usually incased with leather cover portions which are cut out of prepared hides inpredetermined sizes and forms. Largely due to these variations, it is necessary that the forms be cut in slightly smaller sizes than otherwise would be necessary. This is due to the fact that the prepared leather cannot be shrunk and therefore any adjustments that are necessary must'be made by stretching.

The fitting of the ball cover portions individually to .each ball center is a work requiring skilled labor and tedious adjustment. This fitting of the cover individually to each ball center is therefore quite an expensive operation which adds materially to the cost of the finished product. Furthermore, the amount of stretching necessary varies considerably with each ball. As the bounce or resiliency of the ball is to a certain extent dependent upon the tension under which the covers are secured, it is almost impossible under this known method to produce balls having standard resiliency.

This invention contemplates the provision of ball centers and a method of making them in which the above mentioned defects are largely obviated. Ball centers constructed in accordance with our invention are substantially waterproof, do not appreciably vary in their weight, form, or other desirable characteristics, and may be manufactured in an economical and efiicient manner.

The further purposes and the full nature of our invention will be understood from the accompanying description, drawing, and claims forming a part hereof. In the drawing:

Fig. 1 is an elevational view of a ball center made according to one method embodying our invention.

Fig. 2 is a section taken along the line 2-2 of Fig. l.

Fig. 3 is a corresponding sectionalview of a ball center made according to a modified method embodying our invention.

Referring now to the drawing, the numeral i indicates the preferred ball center of our invention which is produced by compression of fibers 2 such as, for instance, kapok. These fibers after being weighed are felted and compressed together in a thoroughly crisscrossed manner ina suitable mold which is preferably heated until the outer surface portion of the fibers is baked or fused sufilciently to provide a semi-rigid shell 3. With sufficient pressure, fusing of the shell may 'occur without baking. formed under various conditions, but in practice, it has been found that subjecting the ball centers to a heat of from 600 to 700 F. for a period ranging from eight to ten minutes is sufiicient to give the shell its desired properties.

Upon removing the article I from the mold, it will be found that a ball center has been produced which is, within exceedingly small limits, of predetermined shape, size, weight, and performance. In manufacturing this ball center, it is desirable that the fibers be first thoroughly criss-crossed. This crisscrossing of the fibers can be done in numerous ways but the preferred way of accomplishing this is to pass the loosely lumpedwads of fiber through a picker, such as is used for picking hair for mattresses. Aftr passing through the picker the fibers are discharged This shell 3 may be in suspension and settle in a crisscross manner to form a loosely felted mass. For convenience, the fibers should preferably be allowed to settle from suspension in a portable container which can be moved to a location convenient to the molding operation. In placing the crisscrossed fibers on a scale to be weighed, the operator should be careful to remove in one bunch at least a sufilcient mass of fibers to form a ball center. In order to do this consistently, the operator should remove slightly more than enough of the fibers to make the correctweight. Any excess fibers should be placed in a separate container and again passed through the picker or otherwise crisscrossed.

.The proper crisscrossing of the fibers is an important feature of this invention. as it has been found by test that when the fibers are properly crisscrossed the ball center does not break so easily and does not have hard spots on various parts of the surface. It is also important that the fibers be removed from the container in one bunch as removing them in several bunches causes planes of cleavage to form within the ball along which planes the ball is easily split.

Now referring more particularly to Fig. 3, 4 indicates a portion of a ball made by a modified method of our invention which consists of compressed crisscrossed fibers 5 and a shell portion 6. The shell portion 6 may be made of any suitable binding material which, with or without baking, forms a hard shell. A number of synthetic resins 'are suitable for this purpose such as, for instance, a molding compound popularly known as "Durez,'a phenol-aldehyde resin containing ground vegetable fiber. Various other plastics may be used, such as rubber compounds, cellulose esters, etc.

According to this embodiment of our invention, the ball center is preferably made of fibers which have been previously run through a picker.

These fibers are also compressed ina mold in much the same manner as are the fibers 2 of Fig. 2. Before placing the fibers in the mold. however, the material out of which the shell is made is suitably applied to the inner surface of the mold, After molding and baking, or other suitable treatment according to the nature of the plastic, it will be found that the blndlnK material placed in the mold will have formed a solid waterproof shell which has the desired physical characteristics.

We claim:

l. A method of manufacturing fibrous ball centers of the class described, comprising arranging separated vegetable fibers in crisscross relation, placing said fibers in a spherical mold lined with a phenol-aldehyde plastic, and subjecting the material in the mold to heat and pressure so as to produce an article having a hard semi-rigid shell.

2. The method of manufacturing fibrous ball centers of the class described, said method comprising separating vegetable fibers, placing the fibers in gaseous suspension, collecting the fibers from suspension, compressing the collected fibers in a spherical form, and baking the form until the fibers on the outer surface of the form are fused together.

3. A method of manufacturing fibrous ball centers of the class described, comprising arranging kapok fibers in crisscross relation, placing said fibers in a spherical mold lined with a phenol-aldehyde plastic, and subjecting the material in the mold to heat and pressure so as to produce an article having a hard semi-rigid shell.

4. The method of manufacturing fibrous ball centers of the class described, said method comprising separating kapok fibers, placing the fibers in gaseous suspension, collecting the fibers from suspension, compressing the collected fibers in a spherical form, and baking the form until the fibers on the outer surface of .the form are fused together.

CARLTON C. DAVIS. JESSE HOWELL GREGORY. 

